Interpretive Summary: There is an increasing awareness of the need for research into dietary intakes of vitamin D in the U.S. The Beltsville Human Nutrition Center's Nutrient Data Laboratory (NDL) is in a unique position to be able to oversee the analyses of foods believed to be good sources of vitamin D in the U.S. diet and to provide these data to researchers and the American public through its primary database, the USDA National Nutrient Database for Standard Reference (SR). In addition, these data will be available for use in the Food and Nutrient Database for Dietary Studies (FNDDS). The first step of the vitamin D program was working with expert analysts to determine what methods are best suited for analyzing vitamin D in a variety of food types. While analytical methods were being tested, and in some cases modified, NDL prepared a list of foods to be sampled and analyzed. The list of foods includes fish, a natural source of vitamin D, and the following foods which may be fortified with vitamin D: fluid milks, orange juice, ready-to-eat breakfast cereals, margarine and spreads, sliced American cheese, and yogurt. Additional vitamin D data for commercial foods not sampled for analysis will be requested from manufacturers. Analytical data and data from the food industry will be released in SR. Additional vitamin D values will then be calculated for the remaining foods needed for the NHANES: What We Eat in America Food Consumption Survey. The database of vitamin D values will be useful to Americans who are interested in eating a healthy diet and will help public health professionals assess vitamin D intake and needs in the U.S.

Technical Abstract:
Recently, the scientific community has focused attention on the need to assess the dietary intake of vitamin D. Specific data are needed on the forms of vitamin D, including D2 and D3, which can occur in foods, both naturally or from fortification. The Nutrient Data Laboratory (NDL), BHNRC, ARS, USDA collaboration with recognized vitamin D experts has initiated an analytical program, with 2 major goals: 1) to review and develop methodology for analyzing items across a wide range of food matrices and 2) to sample and analyze foods considered to be major contributors of vitamin D in the U.S. diet. During 2007 analysts from five labs tested available methods on selected food matrices and compared their results. Methods have been tested, modified in some cases, and validated against matrix-matched quality control samples to prepare for the analysis of sampled foods. To set priorities for analysis, NDL has identified fortified foods which are important contributors of vitamin D: fluid milks, orange juice, ready-to-eat breakfast cereals, sliced American cheese, margarines, and yogurt. Fish were identified as good sources of naturally occurring vitamin D. A nationwide multi-stage sampling plan was designed and conducted to select and procure representative sample units of all foods of each type. Following the analysis of food samples and the review of results, acceptable values for Vitamin D2 and D3 will be disseminated in the National Nutrient Database for Standard Reference (http://www.ars.usda.gov/nutrientdata) for use in the assessment of intake of Vitamin D.